TREATMENT OF MALIGNANTHYPERTHERMIA IN AN OUTPATIENT SURGERY CENTER Are you prepared? Presented by Kelly Parkes Wilson, RN, LHRM
WHAT IS MALIGNANT HYPERTHERMIA? “Malignant Hyperthermia (MH) is a biochemical chain reaction response triggered by commonly used general anesthetics and the paralyzing agent succinylcholine, within the skeletal muscles of susceptible individuals.” - MHAUS.org MH is a rare but deadly hypermetabolic event. Complications include cardiac arrest, brain damage, internal bleeding, organ system failure and death, due to cardiovascular collapse.
PATHOPHYSIOLOGY OFMALIGNANT HYPERTHERMIA Patients susceptible to MH have a defective calcium channel on the sarcoplasmic reticulum of the skeletal muscle cells. Symptoms arise from hypermetabolism of skeletal muscles, probably as a result of uncontrolled release of calcium from the sarcoplasmic reticulum and calcium entry from the extracellular space or decrease in calcium uptake. Resulting in sustained, uncoordinated muscles contraction and metabolism increases, massive oxygen consumption and production of lactic acid, heat and carbon dioxide.
PATHOPHYSIOLOGY OFMALIGNANT HYPERTHERMIA Rapid ATP consumption Cellular acid content increases Cell membranes breakdown Muscle break down begins (rhabdomyolysis) Cardiac changes - tachycardia and dysrythmia, hypotention, decreased cardiac output, cardiac arrest. Lab indicators Creatine kinase – high levels indicate muscle breakdown Potassium (hyperkalemia) – leads to cardiac arrest
WHO IS SUSCEPTIBLE? So who is susceptible? MH is inherited with an autosomal dominant inheritance pattern linked to as many as 80 genetic defects. Carriers with susceptibility often are unaware they are at risk. The rate of occurrence is estimated to be as frequent as 1 in 200 cases or as rare as 1 in 65,000. Children and young adults are at greater risk. As many as 5% do not survive an MH event. A susceptible patient may have previous surgeries, exposed to triggering agents, without a reaction but have an MH crisis in subsequent exposure.
SO WHAT ARE WE DOING TODAY?The goal of today is to address how an MH crisis would be treated at this facility.Prevention: Preoperative questions & planningRecognition Recognize signs and symptomsTreatment: Response/duties cards Introduction to the emergency cart. Walk through a mock code.Transfer: Discuss transfer protocol.
PREVENTION:PREOPERATIVE QUESTIONING It is important to ask questions regarding the patient’s anesthesia & health history as well as family member’s history. If there is any concern or red-flag regarding susceptibility to MH, contact the anesthesia provider. Preparation for a possible MH patient is critical. Prevention is the best treatment!
PREVENTION:PREOPERATIVE QUESTIONING (CONTINUED) History and Physical appointment should ask about any anesthesia problems in the patient’s past or any family members’ past. The conversation should include questions to exploring the subject of MH. Has you ever had a “bad” reaction to anesthesia? Have you or a family member had a problem with anesthesia? Have you or a family member had a fever while under anesthesia? Has a family member died unexpectedly in the OR? Have you or anyone in your family experienced a heat stroke that resulted in hospitalization? Have you ever noticed dark “cola-colored” urine after general anesthesia or after a heat-related illness? Do you or anyone in your family have a neuromuscular disorder?
PREVENTION:PREOPERATIVE PLAN Malignant hyperthermia can be avoided by eliminating triggering agents. Educate the patient that, if they are a susceptible patient, that does not mean his/her case would be cancelled. Patients CAN have outpatient surgery even if they have had previous MH event or a family history. Talk to the anesthesia provider if you have a patient you are concerned about. Have a plan, have appropriate supplies, educate and practice.
PATIENT WITH KNOWN OR SUSPECTED MHHAVING ELECTIVE SURGERY Patients can have had an uneventful anesthesia in the past but still have an MH reaction in a later surgery. Do not assume there will be no MH reaction if the patient had an uneventful surgery before. Dantrium (dantrolene) capsules are available as a prophylactic for patient with suspected MH, but not widely used. Decision would be made by anesthesia provider to use prophylactic treatment. Avoidance of triggering agents is primary prophylactic approach.
PATIENT WITH KNOWN ORSUSPECTED MH HAVING OUTPATIENSURGERY (CONTINUED) Pre-inform anesthesia provider. Schedule as first case of the day. No Triggering Agents to be used!! Be prepared with dantrolene& MH cart. Closely monitor early signs of MH. Any patient suspected of MH should remain in PACU for 4 hours for monitoring.Testing is available at special centers. Susceptibility is determined by the caffeine-halothane contracture test which involves taking a biopsy of skeletal muscles. Information regarding testing can be found at www.MHAUS.org.
EARLY RECOGNITION OF MH Generally first diagnosed by anesthesia provider Early diagnosis is critical for patient survival MH symptoms can initiate in PACU Signs and symptoms Elevated end tidal CO2 or tachypnea Increase oxygen consumption Tachycardia & PVC’s Cardiac arrhythmia Unstable blood pressure Sweating, mottled skin Masseter spasm Generalized muscle stiffness or rigidity Metabolic and respiratory acidosis
LATE SIGNS & SYMPTOMS OF MH Elevated temperature Temperature can increase 1.8° F every 3 minutes Metabolic and respiratory acidosis Presence of creatine kinase Hyperkalemia Hypercalemia Dark urine (myoglobinuria – myoglobin in urine) Severe cardiac arrhythmia and cardiac arrest Disseminated intravascular coagulation (DIC) Left ventricular failure – pulmonary edema - death
PROMPT TREATMENT Early Treatment – Anesthesia will run the crisis! Dantrolene mixed and administered quickly . Initiate transfer protocol. Effective Treatment ALL HANDS ON DECK! Working as a prepared team. Act Quickly…SAVE A LIFE
TREATMENT: EMERGENCY ABCD’S OFMALIGNANT HYPERTHERMIAA = Agents – stop all triggering agents Administer non-triggering anesthetics Ask for help Ask for MH CartB = Breathing – hyperventilation with 100% oxygenC = Cooling procedures if patient is > 102.2D = Dantrolene – continuous rapid IV push
USE YOUR RESOURCES - YOU’RE NOT ALONE! Call for all nurses to report to the OR! “Code MH” (or other designated code) Call the 1-800 644-9737 to speak to MHAUS Hotline. Anesthesia provider should speak with them on a cell phone. Pull MH Emergency Response Cards and assign 4 nurses their duties. MHAUS wall posters available from MHAUS.
CIRCULATING NURSE Call for help – assign nursing duties (dantrolene, medication and cooling nurse). Assign someone to call 911….critical step! Assign someone to inform other anesthesiologist if available. NO NEW CASES TO START IN THE OTHER ORs – ALL HELP NEEDED FOR MH CRISIS Assign someone to notify the surgery center manager and/or administrator of the situation.
CIRCULATING NURSE Assist anesthesia as needed to: Call MHAUS – number on treatment cards Change circuit & soda absorbent (have with MH supplies). Start large bore IV – discontinue LR and hang N/S. Draw labs/urine specimen. You are still circulating so keep the surgery in mind. Help the surgeon/scrub close or pack for transfer. What you cannot do – DELEGATE!
DANTROLENE SODIUM- THE drug for MH Dantrolene acts as a skeletal muscle relaxant by acting on calcium channels, suppressing the rise of calcium in muscle cells that trigger the MH response. Dantrolene is generic name. Dantrium and Revonto are name brand. Reconstitute with preservative-freesterile water. Each facility should have 36 vials on hand, located close to the OR, with code cart is logical location. Sharing vials with other facilities is not recommended. Average of 30 vials used per crisis. IV Dantrolene treatment will continue during transportation and up to 36 hours in ICU.
DANTROLENE NURSE Obtain code cart if not already in the OR. Start mixing dantrolene (skeletal muscle relaxant). Each vial has 3g of mannitol included (renal vasodilator). Mix with preservative-free sterile water 60ml sterile water per dantrolene vial Create a fluid path with short IV tubing and stopcock for rapid mixing. Use spikes for rapid injection into vial Shake until clear - 2 ½ - 4 minutes to mix. (New quick- mixing versions make reconstitution much easier and quicker).
DANTROLENE NURSE Get all the help that you can to mix the dantrolene. A minimum of 2-4 people needed. Rapid IV push of dantrolene once diluted. Initial dosing of dantrolene = 2.5 mg/kg (20mg/bottle) Quick conversion dosage chart located on MH cardsWeight Initial Dose via rapid IV push 110lb = 50kg 125mg 6.25 vials 132lb = 60kg 150mg 7.5 vials 154lb = 70kg 175mg 8.75 vials 176lb = 80kg 200mg 10 vials 198lb = 90kg 225mg 11.25 vials 220lb = 100kg 250mg 12.5 vials Send dantrolene vials with patient during transfer for continued treatment.
MEDICATION NURSE Therapy aimed at treating hyperkalemia, acidosis, arrhythmia and increasing urinary output. Medications to be prepared to give Sodium Bicarbonate (treat metabolic acidosis) Furosemide (increase urinary output) Dextrose (treat hyperkalemia) Calcium chloride (treat hyperkalemia) Regular insulin (treat hyperkalemia) Lidocaine (treat arrhythmias) Amiodarone (treat arrythmias)
MEDICATION NURSE - DOCUMENTATION Record keeping Assign recording to another person if available Specialized “Malignant Hyperthermia Critical Intervention Record” is available from MHAUS Complex form – be familiar with the form before you need to use it Focus documentation on: Medications given Time given Dosage Patient response Nursing interventions Cooling measures
COOLING NURSE Discontinue warming blanket if in use. Provide anesthesiologist with an esophageal temperature probe (should be with MH supplies). Cooling protocol starts at 102.2°. Patient warms at a rapid rate so begin gathering cooling supplies even if patient is not at treatable temperature.
COOLING NURSE Cooling techniques: Cold IV and bottled sterile saline in refrigerators. Cool the patient surface by putting ice packs to groin, axillea and head Be prepared to lavage stomach, bladder and rectum with cold saline. Provide cold sterile saline for lavage of open cavity. Discontinue cooling measures when temperature decreases to 100.4 °> to avoid hypothermia.
SO, WHAT’S MY JOB? You do not know which job you will have during an MH event so you must be familiar with all 4 nurse assignment. All 4 nurses’ responsibilities will be important and stressful.
CODE & MH CART Keep it stocked and organized. Take time to go through the cart and be familiar with the contents. Keep ice available. Cold saline in refrigerator.
WHAT’S SHOULD BE INEMERGENCY CART?Medications Supplies Dantrolene – 36 vials Anesthesia circuit and Sterile preservative free water sodasorb Sodium Bicarbonate 8.4% (50ml Temperature probe x 5) 60 cc syringes Furosemide Mini-spikes (40mg/amp x 4 amps) Fluid transfer tubing Dextrose 50% (50ml vials x 2) N/G tube & Toomey syringes for irrigation Calcium Chloride Foley 10% (10ml vial x 2) Zip baggies for ice packs Regular Insulin (100 units x 1 refrigerated) Large bore IV’s Lidocaine preloaded syringes ICE & 3 Ls of cold IV and (100mg) x 3 or Amiodorone bottles saline in refrigerator
A CLOSER LOOK at MEDICATIONS Dantrolene – muscle relaxant Sterile preservative free water – for dilution Sodium Bicarbonate – treat metabolic acidosis and hyperkalemia Furosemide – maintain urine output Insulin & Dextrose - treat hyperkalemia Calcium Chloride – treat hyperkalemia Lidocaine or Amiodorone - treat dysrhythmias
TRANSFER PROTOCOL Outpatient surgery centers have the added obstacle of having to transfer the patient to an inpatient facility for complete treatment of an MH event. Call 911 early to begin transfer process. Direct personal communication – anesthesia to physicians at the hospital – is strongly recommended. Have a “Transfer of a Patient” protocol in place and make sure everyone knows where it is and how to use it.
TRANSFER PROTOCOL Patient should be moved when, according to anesthesia, the patient is showing signs of stability. Anesthesia provider will make decision of timing of transfer. Signs of stability are: EtCO2 in declining Heart rate is stable or decreasing with no ominous dysrythmias Dantrolene administration has begun Temperature is normal or declining If present, generalized muscular rigidity is resolving
TREATMENT AT A GLANCE“Some hot dude better give iced fluids fast” Stop triggering agent Hyperventilate with 100% O2 Dantrolene Bicarbonate Glucose and Insulin Ice and cooling measures – lavage, surface & wound Fluids – IV fluids in and Lasix for output Fast – treat tachycardia/V-tach
TIME TO DO A MOCK CODE!REMEMBER….. Take this opportunity to practice without harming a patient. Be comfortable – you’re among friends. You can’t make a mistake here.
REFERENCES AORN Perioperative Nursing Video Library (2009). Video: Malignant Hyperthermia; Keeping your cool [DVD video]. USA:Cine-Med. Helmer, M. & Carlson, K. (2010). Malignant Hyperthermia: Perioperative crisis [PowerPoint slides]. Retrieved September 27, 2010 from http://www.nursingceportal.com/CECourses/Description/38 MHAUS (2010). Guide to malignant hyperthemia in an anesthesia setting. Available at www.mhaus.org MHAUS (2010). Transfer plans for suspected MH patients [poster]. Available at www.mhaus.org Reno, D. (senior editor.) (2008). Perioperative standards and recommended practices (2008 Ed.). Denver: AORN